Ph.D Student @ State University of New York Stony Brook
Perhaps the single most important sign of death is the persistent absence of breathing. We have to continously exchange gases with the environment to mantain homeostasis and support our highly metabolic rate. The drive for continuos ventilation is strong and resides in the most primitive areas of the brain, like the brainstem. Automatic breathing persists even when cortical function has been lost. Therefore, automatic ventilation allow us to mantain homeostatic levels of O2 and CO2 in our body with out the input of higher brain functions. How do we achive this syncronous, yet flexible, response? One of the main reasons is that we have neurons that are in charge of monitoring the level of this gases in the blood, and thet alter ventilation patterns by modifing their electrical discharge accordingly. These neurons, called chemosensitive neurons, are capable of transducing the signal, which could be, increase CO2, increase HCO3, low outside pH pHo, low inside pH pHi, or a combination of these, into a very unusual reponse for a cell, which is lack of regulation of pHi.
This observation is object of much research now and one of the projects in our lab. With a theoretical approach (a mathematical model) we explore a series of hypothesis that we expect them to lead us to a better understanding of neuronal pH regulation in general, and chemosensitivity in the brainstem.
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Institution
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Program
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Finished
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| Universidad de los Andes | B.Sc. Civil Engeeniring | 09/1997 |
| Universidad de los Andes | B.Sc.Biology | 09/2000 |
| State University of New York | M.Sc. Biomedical Engineering | 07/2006 |
My research as PhD student involves mainly the development and testing of a mathematical model of CO2 chemosensitivity in central chemoreceptors. The model is based on the Goldman-Hodgkin-Katz (GHK) equation to account for nonlinearities of the I/V relationship and incorporates conservation of mass and electroneutrality constraints, kinetic models of the Na+/K+ ATPase, Anion Exchanger, NHE isoforms (believed to play a primary role in CO2 sensing), and passive permeation pathways for ions, non-electrolytes, and H2O.
· Juan M. Cordovez, Chris Clausen, Leon C. Moore, and Irene C. Solomon. A Mathematical model of pHi regulation in central CO2- chemoreception. FASEB. Washington. USA April 28 2007.
· Juan M. Cordovez, Chris Clausen, Leon C. Moore, and Irene C. Solomon. A mathematical model of pHi regulation in central CO2- chemoreception. 3rd Annual Northeast Bioengineering Conference. Stony Brook. New York. March 2007.
· Cordovez, J.M.; Clausen, C.; Moore, L.C.; Solomon, I.C.; A Mathematical model of pHi regulation in central CO2- chemoreception. Integration in Respiratory Control - from Genes to Systems (Advances in Experimental Medicine and Biology Series). Eds: M.J. Poulin and R.J.A. Wilson. Springer Publishers, New York. In Press. (ISBN-13: 978-0-387-73692-1).
· Cordovez, J.M.; Clausen, C.; Moore, L.C.; Solomon, I.C.; A Mathematical model of pHi regulation in central CO2- chemoreception. Xth Oxford Conference. Lake Louise. Canada. September 2006.
· Cordovez, J.M.; Clausen, C.; Moore, L.C.; Solomon, I.C.;Differences In pHi Recovery In CO/sub 2/-Chemosensitive And Non-Chemosensitive Cells: Predictions From A Mathematical model. Engineering in Medicine and Biology Society, 2006. EMBS '06. 28th Annual International Conference of the IEEE. Volume Supplement, 2006 Page(s):6589 - 6592
· Cordovez, J.M.; Clausen, C.; Moore, L.C.; Solomon, I.C.;PHi regulation in central CO2-chemosensitive and non-chemosensitive cells: A mathematical model. FASEB. San Francisco, CA. USA. March 2006.
J.M Cordovez, T. Greenberg, B. Ravindranath, M. Korgaonkar, LR Mujica-Parodi. System Identification of the Excitatory and Inhibitory Components of Human Arousal Response. BMES Abstract 142156 / October 1st 2005.